Hydrodynamic transmission



April 10, 1.-.945. E.|.A BRIE V 2,373,122

I v HYDRODYNAMIC TRANSMISSION Filed April 16, 1942 INVENTOR I uqger E arze.'

ATTORN EYS.

' nating the necessity for the usual Patented Apr. 10, 1945Y 2,373,122 nYpRonYNAMrc 'mANsMIssIoN Ludger E. La Brie, Detroit, Mich., assigner to Chrysler Corporation, Highland Park, Mich., a

corporation of Delaware Application April 1s, 1942, serial No. tziailsi` (ci. 741s9.5)

13 Claims.

This invention relates to vehicle power transmissions and the main object is to provide a combined hydraulic and mechanical transmission which is automatic in operation, simple in design and which provides adequate speed ratio variation for satisfactory operation in conventional types of motor cars.

.A further object is to provide in such a transmission means for locking the driven shaft against movement relatively to the casing thereby elimiparking brake mechanism.

Other objects and advantages will be apparent from the following 'description taken in conjunction with the accompanying drawing, in which a preferred embodiment of the invention is illustrated. p

In the drawing, the single figure shows a side elevation of my improved transmission, partly insection. Y

The transmission comprises a three section casing, the front portion I housing the hydraulic unitl the central portion II housing the reverse gearing and the rear portion I2 housing the overdrive unit.

The hydraulic unit includes a torque connector having an impeller I3 connected to the' engine crankshaft by means of the housing i6, a runner or turbine I4 and a'guide wheel I5. The runner is bolted at Il to an intermediate driven shaft I8 and this latter shaft has a hollow portion I9 into which is piloted the rear end of a shaft which' forms part of the housing It. An overrunning roller clutch 2l is operatively disposed between the shafts I8 and 20 for preventing overrun of the shaft I8. A The guide wheel I5 has a rearwardly extending sleeve 22 which has an overrunning brake connection with a brake member 23 carried by the casing. The over-running brake includes rollers 2t which permit the guide wheel to rotate forwardly but prevent it from rotating ln reverse An overrunning clutch 25 is operatively disposed between the guide wheel and the .shaft I8 for clutching .the guide wheel to the shaft in the forward direction of rotation and for permitting the shaft to overrun the guide wheel in this same direction.

The shaftl'terminates rearwardly in a sun gear 26 which is hollow and pilots the hub v2'I of an annulus 28. The latter has gear teeth 23 formed thereon; which teeth mesh with planet pinions 30 carried by a carrier 3l. The pinions 30 also mesh with the sun gear 28. 1

t valve' 4l.

The annulus 28 also carries a set of clutch plates 33 which are adaptedto engage similar plates 32 carried by the carrier 3l. A cylinder 34 formed in the annulus 2t carriesy a piston 35 which bears on the clutch plates and urges them into engagement when pressure -fluid is admitted Vto the cylinder as will be presently explained.

The annulus 28 carries a set of external teeth 36 and the carrier is provided with a similar set of teeth 3l. These teeth are adapted to be engaged by the teeth 38 of a slidable sleeve 39 which is mounted in the casing Il for sliding on the spline teeth Mi, a lever 4l being provided for shifting the sleeve. f

The impeller I3 has a. rearwardly extending sleeve portion 42 on which is 'splined a pump drive gear 43. This 'gear drives a pump shown diagrammatically at M, the input t5 of .which is connected to the interior of the casing lli.

The pump output conduit 46 is connected to a valve 4l which may be positioned on any suitable part of the vehicle. The valve lll has a drain conduit 48 which leads back to the casing lll andis connected by a link 66 with the lever 4l sucllA that the -valve andsleeve 38 are actuated in unison by any type of'suitable manually operatedl control, l Y

The valve 4l has four positions as diagrammatically indicated on the drawing. In neutral position (as illustrated in full lines) the sleeve 39 is in extreme forward position andthe pump 44 is exhausting in the drain pipe 48 through the Under tnese conditions the carrier 3i and the' annulus 23 are both free so no rotation is imparted to the driven shaft 5l which is shown as an integral part of tne annulus, but whic may be separate therefrom if desired.

Shift of the valve member to forward po sition cuts o fl communication between the pump 44 and the drain passage 48 and causes pressure to' build up in conduit 48 and'cylinder 34 whereupon piston 35 is caused to move forwardly. and

ward speed. the guide wheel I5 of the torque connector being prevented froinvreverse rotation by the overrunning brake thus furnishing reaction for the unit.

When the vehicle has attained suiiicient speed such that the impeller and runner tend to rotate at substantially the same speed, the reaction forces on the vanes of the guide wheel i5 will disappear and the guide wheel will be urged forwardly by the impelled iluid. The brake 2li will thenautomatically disengage and the clutch 25 will automatically engage to lock the guide wheel to the shaft I8 whereupon it serves as anv auxiliary runner. y

The transmission is, under these conditions, operating in what is practically direct drive, the hydraulic unit functioning as a uid coupling of the kinetic type.

Shift to a higher speed ratio in the overdrive mechanism is preferably accomplished by automatic speed responsive means. Inasmuch as the details of the overdrive mechanism are unimportant so far as the present invention is concerned, no description thereof will be given. An overdrive of the type described and shown in Webb patent, No. 2,236,657, granted April l, 1941, or in the copending application of Neracher ed to be lengaged by said member whereby a reverse driving relation is established between said shafts; and means on said annulus adapted and Dunn, Serial No. 304,060, filed November Shift of the member 55 to park position will engage the sleeve 39 with teeth 31 and teeth 36 while still maintaining the clutch control cylinder vented. This results in the planetary gearing being locked up against rotation relatively to the casing, thus the shaft 51 is rendered nonrotatable, and the vehicle cannot coast or be driven.

It will thus be seen that I have provided an extremely simple and compact transmission which is economical to manufacture, automatic in operation and well adapted for use in light cars. f

I claim: i.

1. In a power transmission, a casing; a driving shaft; a driven shaft; means including a planetary gearset .connecting said shafts; slidable brake means independent of said gearset movable into engagement with one of the elements of said gearset to hold' the same against rotation for transmitting adrive between said shafts, and movable into engagement with at least one additional element of said gearset while still engaged with said one element to hold said additional element of said gearset'against rotation whereby both of said shafts are rendered non-rotatable means independent of said brake nieans operable to condition a pair of elements to be engaged by the same member whereby the driven shaft is locked against rotation.

3. The combination set forth in claim 2 wherein the control member is adapted to engage the carrier and annulus simultaneously to thereby prevent rotation of both of said shafts.

4. In a power transmission, a driving shaft; a uid impeller wheel carried by said driving shaft; a second shaft; a turbine wheel carried by said second shaft; a casing for said wheels and shafts; a, guide wheel disposed in operative relationship to said impeller and turbine wheels; an overrunning brake connection betweenv said guide wheel and the casing for preventing rotation of the guide wheel in the direction of its rotational tendency caused by reaction of the fluid set in motion by the impeller wheel; an overrunning clutch connection between the guide wheel and said second'shaft for permitting said shaft to overrun the guide wheel in forward direction of `rotation but preventing the guide wheel from overrunning 'the shaft in said forward direction; a driven shaft; planetary gearing drivingly disposed between said second shaft and said driven shaft; fluid operated clutch means carried by said gearing for clutching two of the elements thereof together thereby to establish direct drive between said shafts; means including a shiftablemember carried by the casing for engaging one of the elements of said gearing thereby to establish reverse drive between said shafts.

5. In a power transmission, a driving shaft;

va iiuid impeller wheel carried by said driving wheel and said second shaft for permitting said shaft to overrun the guide wheel in forward direction of rotation but preventing the guide wheel from overrunning the shaft in said forward direction; a driven shaft; planetary gearing drivingly disposed between said second shaft and said driven shaft; clutch means carried by said gearing for clutching two of the'elements thereof together thereby to establish direct drive between said shafts; means including a shiftable member carried by the casing and adapted for shifting to engage oneI of the elements of said 'a second shaft; a turbine wheel carried by said second shaft; a casing for said wheels and shafts; a guidevwheel disposed in operative relationship to said impeller and vturbine wheels; an over? running brake connection between said guide wheel and the casingfor preventing rotation of the guide wheel in the direction of its rotational tendency caused -by reaction of the'iiuid set in motion by the impeller wheel; an overrunning clutch connection between the guide wheel and thereby to establish direct drive between said shafts; means including a shiftable member carried by the casing and adapted for shifting to' engage one of the elements of said gearing ythereby vto establish reverse drive between said shafts and two of the elements of said gearing thereby to lock said shafts from rotation; fluid pressure means for controlling said. clutch; manually operable means for controlling said shiftable member, and interlocking control means for maintaining said clutch disengaged when said shiftable member is in an operative position.

7. In a power transmission, a driving-shaft; a driven shaft; a sun gear carried by the driving shaft; an annulus gear carried by the driven shaft; a carrier having planet gears mounted thereon disposed in mesh with saidsun and annulus gears; clutch plates carried by said carrier; clutch plates carried by said annulus gear and arranged in interleaved relation with the afore- 'said plates; a fluid cylinder carried by the anl nulus gear; a piston in said cylinder and disposed in operative relation with said clutch plates; a pump driven 'by said driving shaft, valve means .for controlling4 the admission, of pressure fiuid to said cylinder and means also under control of said valve means for simultaneously holding both said carrier and annulus from rotation.

8. In a power transmission, a driving shaft; a driven shaft; a sun gear carried 'by the driving shaft; an annulus gear carried by the driven shaft; a carrierhaving planet gears mounted thereon disposed in mesh with said sun and annulus gears; clutch plates carried by said carrier; clutch plates carried by said annulus gear and arranged in interleaved relation with the aforesaid nplates; a fluid cylinder carried by the annulus gear; a piston in said cylinder and disposed in operative relationwith said clutch plates; a pump driven by said driving shaft and valve means for controlling the admission of pressure fluid to said cylinder; brake means carried by a stationary part of the transmission for preventing rotation of said carrier and said annulus gear: and means interconnecting said brake meansfand said Vvalve whereby said' cylinder is vented whenever said brake means" is engaged.

9. In a powertransmission, a casing, a driving shaft; a driven shaft, means including a planetary gearset connecting said shafts, means for holding one of the elements of said gearset against rotation for transmitting a drive between f said shafts, and means for simultaneously holding at least one additional velement of the said planetary gearset against rotation whereby both of said shafts are rendered non-rotatable, said holdelements engageable with said slidable .tooth means.

10. In a power transmission, a planetary gearset including a-plurality of rotatable elements, power operated means operable to connect two of said elements for unitary rotation. means for controlling operation of said power operated means, means operable'to engage oneor both of said two elements for preventing rotation thereof and means interconnecting said last mentioned means and said power control means for actuating said power operated means to disconnect said two elements when the said last mentioned means is operated to engage one or both of said two elements.

11. In a` power transmission, a casing, a driving '.sbaft, a driven shaft coaxial with the driving shaft, a planetary gearset for drivingly connecting said shafts including an input element, an

output element and a third element all rotatable about the axis o f said shafts, a set offclutch plates carried by said output element, a set of clutch plates carried by one of said other planetary elements, power operablemeans carried by said output element..for effecting engagement of said clutch plates, -aset of brake teeth carried by one of said clutch plate carrying elements, a brake sleeve rotatably fixed relative to said driven shaft and including teeth shiftable into engagement with said brake teeth, means for shifting said sleeve, means including a movable member for controlling said power operable means, and

means interconnecting said shift means and movable control member and reciprocable thereby whereby said clutch plates are disengaged when said brake sleeve .teeth are engaged with said brake teeth.

12. In a power transmission, a casing, a driving shaft, a driven shaft, a planetary gearset for drivingly connecting said shafts including an input sun gear, an output annulus gear, and a carrier, a brake sleeve slidably carried by said casing and rotatably fixed relative thereto, a set of brake teeth on said carrier, a, set of brake ,teeth on said annulus and means for shifting said sleeve into and out of engagement with one or both sets of brake teeth.

13. In a power transmission for a vehicle having an engine, a driving shaft adapted to receive drive from the engine; a driven shaft adapted to drive the vehicle; a casing for said shafts; a planetary gearset for drivingly connecting-said shafts including an input sun gear, an output annulus. gear and a carrier; fluid pressure operated means operable to clutch the carrier toon'e-f the ing means comprising slidable tooth means on said casing and tooth means on said planetary aforesaid gears for direct drive, said fiuid pressure operated means including an annular piston means for'controlling said uid pressure operated means; manually operable brake means for connecting the carrier tothe casing for establishing reverse drive; and a' common control lever for said clutch and brake operable to actuate said control means for said fluid pressure operated 'means to cause disengagement of said carrier from said one gear when said brake means is operated to connect said carrier to said casing. LUDGER E. LA BRIE. 

